// Copyright 2019 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package util

import (
	"encoding/json"

	"gomodules.xyz/jsonpatch/v2"
	admission "k8s.io/api/admission/v1beta1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
)

// ARFail is a helper function to create an AdmissionResponse
// with an embedded error
func ARFail(err error) *admission.AdmissionResponse {
	return &admission.AdmissionResponse{
		Allowed: false,
		Result: &metav1.Status{
			Message: err.Error(),
			Reason:  metav1.StatusReasonNotAcceptable,
		},
	}
}

// ARSuccess return allow to action
func ARSuccess() *admission.AdmissionResponse {
	return &admission.AdmissionResponse{
		Allowed: true,
	}
}

// ARPatch return admission response that contains a patch to mutate the object
func ARPatch(patch []byte) *admission.AdmissionResponse {
	return &admission.AdmissionResponse{
		Allowed:   true,
		Patch:     patch,
		PatchType: func() *admission.PatchType { p := admission.PatchTypeJSONPatch; return &p }(),
	}
}

func CreateJsonPatch(original, current runtime.Object) ([]byte, error) {
	ori, err := json.Marshal(original)
	if err != nil {
		return nil, err
	}
	cur, err := json.Marshal(current)
	if err != nil {
		return nil, err
	}
	patches, err := jsonpatch.CreatePatch(ori, cur)
	if err != nil {
		return nil, err
	}
	return json.Marshal(patches)
}